Ever feel so frustrated and pent up that even the slightest thing seems like it could set you off? On the verge of rage, but is it truly rage or is it a different emotion - one that defies words but combines anger, frustration, sadness, anxiety, "stressed out" and edginess? Irritability can feel like emotional sandpaper under your skin and once it is in full swing, everything, from a partner's kind words to your dog's whine, seems to make it worse. Typically when we think of depression, we think of the classic symptoms: sadness, low energy, insomnia, appetite changes, and so on. Sometimes, however, depression presents with a slightly different constellation of symptoms, especially in children and young adults. In fact, in children, sadness might not even be present and irritability alone can lead to a diagnosis of depression. The notion of an irritable or agitated depression has been around in mental health treatment for decades, but is not yet supported by the formal diagnostic process for adults. Diagnostic Criteria Currently, the basic criteria required to diagnose depression must include at least five of the following symptoms, and must include either sadness or loss of interest as one of the five: \tSadness, "the blues," low mood, feeling glum, bummed out, or down for no clear reason. \tNo longer being interest in doing things that previously were compelling or interesting. In some cases, this escalates into a complete loss of interest in doing anything at all, and withdrawing from social activity. In other cases, the activity continues but pleasure\/enjoyment ceases. \tAppetite changes that result in weight changes: increases or decreases may be part of depression, but only significant weight loss is noted as diagnostic criterion. \tChanges in sleep patterns: oversleeping (can't get out of bed, sleeping excessive number of hours) or inability to sleep. \tFeeling tired, washed out, and exhausted despite sleeping. \tAn increase in fidgety, purposeless movement such as pacing, nail biting, or chewing the insides of your mouth or a complete absence of such movements (the technical term for this is psychomotor agitation or retardation). \tExcessive guilt and feeling worthless. \tDifficulty concentrating, feeling overwhelmed or unable to complete basic mental or physical tasks; feeling unable to do "normal" activities such as driving, food shopping, answering emails, etc. \tThoughts of death, thoughts of suicide, plans of suicide, or attempting suicide. In adults, a sad mood must be present to diagnose depression. In children, this is not so. The first criteria, sadness or a low mood, need not be present in children if the dominant mood state is irritable. However, in May 2013, a new revision of the Diagnostic and Statistical Manual (DSM) will be released and some changes in understanding depression and irritability in both adults and children are expected. Irritable Subtype? Much has been written about diagnosing depression, and the age exclusion regarding irritability. Studies show that many depressed adults report significant irritability, yet this symptom alone is not sufficient for the diagnosis of depression. Some researchers and clinicians have been arguing for the inclusion of an irritable subcategory of Major Depressive Disorder to help identify, diagnose, and treat this group of depression sufferers. In a study published in 2013 that tracked people diagnosed with depression over a 30-year timeframe, irritability and anger were reported in 54% of these patients. In this study, irritability was defined as being quick to become argumentative, and in more extreme cases, escalated from engaging in arguments to becoming aggressive or even assaultive. This study also linked more severe depressive symptoms with anger. Children and adolescents are particularly prone to this combination of depression and anger, although it can be tricky for parents and\/or caregivers to tease apart these angry depressive symptoms from normal adolescent crankiness. For children identified as at risk for depression, a study published in December 2016 found that irritability and anxiety often precede a depressive episode. What Is Irritability? Quick to anger and quick to tears, most of us know when we are irritable, or more poignantly, we know when those around us are irritable. When children are irritable, they are easily frustrated, have a "short fuse" and may be more prone to acting out behaviorally. Adults also show irritability by becoming easily angered or frustrated, allowing small annoyances to take on inappropriate significance, or having trouble filtering out a sharp word or impatient sigh. In terms of diagnosing a psychiatric illness such as depression, though, clarity and precision are important. Reflect for a moment upon the overlap among feelings of anger, aggression, hostility, and irritability: if irritability is to be featured more prominently in the diagnosis of depression, then it becomes increasingly important to have a clear and precise understanding of this emotion. Irritability is already seen as a diagnostic indicator in several psychiatric disorders, including mania, ADHD, PTSD, and substance abuse. However, researchers note that the definition of this term is lacking precision. Some researchers have advocated for removing irritability as a criteria from a number of diagnoses, and instead creating a working definition of "dysfunctional anger." Whatever it ends up being called, the addition of a mood state other than sadness being key in the diagnosis of depression in some cases is a positive step forward in helping those with this type of depression gain better access to treatment.